Open-hearth furnace



Sept. 22, 1925. 1,554,632

A. HERMANSEN orgm HEARIH FURNACE.

File June 26, 1924 5 Sheets-Sheet 1 l/V VENTOR flxe/ Herman s e n,

A TTORNEYS Sept. 22, 1925.

A. HERMANSEN OPEN HEARTH FURNACE Filed June 26, 1924 5 Sheets-Sheet 2 ill: I

n W II.

l/VVE/V TOR Axe/4 Harmansen,

ATTORNEYS Sept. 22, 1925. 1,554,632 I A. HERMANSEN OPEN HEARTH FURNACE Filed June 26, 1924 5 Sheets-Sheet 5 INVENTOR H 16/ l/ermansen,

Sept. 22, 1925. 1,554,632

A. HERMANSEN 0 PEN HEARTH FURNACE Filed June 26 1924 5 Sheets-Sheet 4 INVENTOR Axel Hermansen,

Patented Sept. '22, 1925.

UNITED STATES AXEL nnnmnsnn, or INGELSTAD, "swnnm orEN-nnmrn run'nacn Application filed June 28,1924. Serial No. 722,495.

' To all whom it may concern:

Be it known that I, AXEL HnRMANsEN, a subject of the Kin dom of Denmark, residing at Ingelstad ard, Ingelstad, Sweden,

have invented a certain new and useful Improvement in Open-Hearth Furnaces of which the following is a full, clear, an ex act description.

My invention relates to furnaces, and has special reference to open hearth furnaces of the type employing recuperators that are in communication with the open ends, respectively, of the melting chamber, for utilizing the heat of the waste gases passing from the melting chamber for the purpose of heating air and directing the heated air into the melting chamber to support combustion. In furnaces of this type it is not possible to utilize in the recuperators all of the heat 20 value in the waste gases, and, consequently, in such furnaces as heretofore constructed a large portion of the heat value in the gases is wasted.

An object of the present invention is to provide a furnace of the character indicated which is capable of being so operated that only a sufiiclent quantity of the waste gases pass to the recuperators as is necessary to supply the requisite degree of heat for their most eflicient operation, while the rest of the waste gases pass to other heat absorption apparatus and thus is put to practical use.

Another'objectof. the invention is to provide an open hearth furnace of the recuperative type which is of simple and compact construction, and economical and highly efficient in operation.

The several features of the invention,

4 jeots may be attained, will be clearly understood from the following description and accompanyingdrawings, in which,

Figure 1 is a lon itudinal sectional elevation taken substantially on the line 11 of Fig. 2 of an open hearth furnace of the recuperative type embodying the features of the invention;

Fig. 2 is a sectional line 22 of Fig. 1;

Figs. 3 and 4 are transverse sectional views taken on the lines 3-3 and 44, respectively, of Fig. 2; Fig. 5 is a sectional plan viewtaken on the line 5-5 of Fig. 4; and

plan view taken on the whereby the above-mentioned and other ob Fig. 6 is a diagrammatical view of the fur- The recuperative open hearth furnace illustrated in the drawings is provided with I a melting chamber 2 having the 'usual longitudinally curved hearth 4, top wall or arch 6, and front and rear side walls 8 having suit ably arranged, charge openings 10 and discharge or tapping holes 12. Each end of the tending longitudinally of the furnace, where they are in communication with each other through a passage 18 extending longitudinally of the furnace. The passage 18 is 'in' communication through passages 20 with the air outlet ends of recuperators 24 and 26 which are arranged adgacent the left and right hand ends, respectively of thefurnace,

and are mounted on the bottom wall of'the furnace a distance in front of the melting chamber 2. Air is admitted to eachof the recuperators through conduits 28 leading into the air inlet end of the recuperator and provided with a sliding damper 30.

The passage 16 in the right hand end of the melting chamber extends a distance outwardly, then vertically downwardly to the bottom of the furnace, beneath the lower end of the adjacent pasv sage 14 to the gas inlet end of the recuperator 26. The gas outlet end of this recuperator'is in communication through a passage 32 with the inlet opening 34 of a boiler chamber 36 in which is arranged a water tube boiler 38. This boiler chamber is provided with a gas outlet passage 40 which leads through a flue 42, having a sliding damper 44, to a stack 46. Y

The passage 16 in the left handvend of the melting chamber extends outwardl then downwardly to the bottom of the rnace, then forwardly beneath the lower end of the adjacent passage 14, and then inwardly to the gas inlet opening 48 of a furnace chamber 50 in which there is mounted a water tube'boiler 52. The gas outlet opening 54 of this furnace chamber is in communication through a passage 56 with the gas inlet end and then forwardly" ignited fuel in the two passages 14 each traverse a more or less i of a horse shoe path, as indicated by arrows in Figs. 2 and 6, to substantially the center of the smelting chamber, and then out through the ad jacent gas outlet passage 16. The hot gases entering the discharge passage 16 at the right hand end of the melting chamber, pass through said passage to the recuperator 26, and after passing through the recuperator pass out through the passage 32, through the boiler 38, and then out through the flue 42 to the stack 46. The hot gases entering the passage 16 at the left hand end of the melting chamber, pass through this passage to the boiler 52, and after passing through the boiler pass through the passa e 56, the recuperator 24, and out through t e flue 58 to the stack 46. v

24 and The air entering the recuperators 26 through the passages 28 pass through the passages 20, respectively, to the common passage 18 where the. two streams of air meet to effect equalization oftemperature thereof. Air from the common assage 18 then passes at a substantially uniform temperature up through the passages 14 where it mixes with the fuel from the supply pipes 62 to support combustion.

From the foregoing it will be apparent that the waste gases passing from the right hand end of the furnace chamber pass first through a recuperator where a substantial part of the heat value thereof is given up to the air entering the recuperator, and then passes through a waste heat boiler which absorbs as much as possible of the remaining amount of heat value in the gases, before the gases pass to the stack; and that the hot gases passing from the left hand end of the furnace pass first through the.

water tube boiler 52 where a substantial part of the heat value of the gases'is given up, and then passes through the recuperator to the stack. By this arrangement it is possible for the recuperators and boilersto absorb all of the heat value of the waste gases with/the exception of a suflicient deend of the melting chamber, and one of the recuperators receives the direct heat of the hot gases emerging from the other end of the chamber. By mixing the two streams of heated air passing from the recuperators so as to equalize their temperature, and then single wall Which may be of high heat insulating material, and the arrangement of these apparatus in front of the melting chamber permits easy access thereto. With the arrangement of the recu erators and boilers as illustrated in the rawings, the waste gases will enter the recuperator 26 and the boiler 52 at substantially the temperature that they leave the melting chamber. It may be noted that the dampers 30, 44 and 60 are all located beyond the recuperators and boilers so that none of them is subjected-to the intense heat of the'waste gases leaving the melting chamber.

As will be evident to those skilled in the art, my invention permits of various modifications without departing from the spirit thereof or the scope of the appended claims.

lVhat I claim is:

1. A furnace of the class described having, in combination, a melting chamber, recuperators associated with the ends of said chamber, respectively, heat absorption apparatus associated with the ends of the.

chamber, respectively, and suitable means for conducting waste gases from one end of said chamber first through the recuperator and then through the heat'absorption apparatus associated therewith, and for conducting hot gases from the other end of the chamber first; through the heat absorption apparatus and then through the recuperator associated therewith.

2. A furnace of the class described hav ing, in combination,- a melting chamber, recuperators associated "with the ends of said chamber, respectively, heat absorption apparatus associated with the, ends of the chamber, respectively, and suitable means for conducting waste gases from one end of said chamber first through the recuperator and then through the heat absorption apparatus associated therewith, and for con ducting waste gases from the other end of the chamber first through the heat absorption apparatus and then through the re cuperator associated therewith, and means then directing it into the melting chamber through both ends thereof.

3. furnace of the class described having, in combination, a melting chamber, recuperators associated with the ends of said chamber, respectively, heat absorption apparatus associated with the ends 'of the chamber, respectively, suitable means for conductin waste gases from one end of said chamber rst through the recuperator and then-through the heat absorption apparatus associated therewith, and for conducting waste gases from the other end of the chamber first through the heat absorption apparatus and then through the recuperator associated therewith, a conduit connecting the air outlet ends of said recuperators, and means for directing air from said conduit into the melting chamber through both ends thereof.

4. A furnace of the class described having, in combination, a melting chamber, a

- recuperator associated with one end of the chamber, a heat absorption apparatus associated with the other end of the chamber,

- means for conducting waste gases from the first mentioned end of the chamber to said recuperator, 1 means for conducting waste gases from the other end of the chamber to said heat absorption apparatus, and means for conducting heated air from the recuperator to the melting chamber.

5. A furnace of the class described having, in combination, a melting chamber, a recuperator associated with one end of the chamber, a heat absorption apparatus associated with the other end of the chamber, means for conducting waste gases from the first mentioned end of the chamber to said recuperator, means for conducting waste gases from the other end of the chamber to said heat absorption apparatus, and means for conducting heated air into the melting chamber through both ends thereof.

6. A furnace of the class described having,

I in combination, a melting chamberhaving a fuel inlet opening and a Waste gas outlet opening in each of its ends, a, recuperator having its gas inlet end in communication with said waste gas outlet in one of theends of the chamber, a heat absorption apparatus having its gas inlet end in communication with thegas outlet end of said recuperator, a second heat absorption apparatus havin its gas inlet end in communication with t e waste gas outlet in the other end of said melting chamber, asecond recuperator having ltsgas inlet end in commumcation with the gas outlet 'end of said last mentioned heat absorption apparatus, and means for bringing the heated air passing from said recuperators together and then directing it into said melting chamber through both of said fuel inlet openings.

7. A furnace of the class described having, in combination, a melting chamber, recuperators associated with the ends of the chamber, res ectively, means for directing waste gases rom the ends of said chamber through said recuperators, and means for mixing the heated air assing from said recuperators and then directing it into said chamber through both ends thereof.

8. A-furnace of the class described having, in' combination, a melting chamber hav'in a fuel inlet and a waste gas outlet in eac of its ends, and a recuperator having its gas inlet in communication with the waste gas outlet in one end of said chamber, and having its air outlet in communication with the fuel inlet in both ends of said chamber.

9. A furnace of the class described hav ing, in combination, a melting chamber having a fuel inlet and a waste gas outlet in each of its ends, a recuperator having its gas inlet incommunication with the waste gas outlet in one end of said chamber, and having its air outlet in communicationwithfifl ing its gas inlet in communication with the gas outlet of said second mentioned heat absorption apparatus, a flue provided with a damper leading from the gas outlet end of said second mentioned recuperator, and a conduit connecting the air outlets of said recuperators and in communnication with the fuel inlet in both ends of the melting chamber.

10. A furnace of the class described having, in combination, an elongated "melting chamber having its front wall provided with charge openings, recuperators located adjacent and in front of the ends of said melting chamber, waste heat absorption apparatus located between said recuperators, said recuperators and waste heat absorption apparatus being adapted to be heated by the Waste gases passing from said melting chamher, and an enclosure for said recuperators and waste heat absorption apparatus having its top wall spaced a distance below the charge opening in the front wall of said melting chamber and projecting forwardly therefrom.

AXEL HERMANSEN. 

